1. Field of the Invention
The present invention generally relates to a subscriber terminal, a base station, a mode switching method, and a wireless system utilizing said method. More particularly, the present invention relates to a subscriber terminal, a base station, a mode switching method, and a wireless system utilizing said method, in which circuit modes are switched.
2. Description of the Related Art
In recent years, a WLL (Wireless Local Loop) has been attracting more and more attention as a wireless subscriber line that is rigidly fixed. Compared with a wired system, a system utilizing the WLL requires neither a large investment nor a long period of time, and is capable of setting a subscriber line in any place where there is a demand in a short period of time at a lower cost. Also, it is possible to establish a long-distance subscriber line suitable for an underpopulated area.
With the WLL system, it is possible to establish a subscriber line without using the existing wired lines in a populated area, and common carriers can provide their service without using the existing wire lines. The WLL is advantageous in the above aspects, and is expected to spread widely in the future. However, the WLL will be used not only for audio communication but also for data communication using facsimile machines and modems.
Conventionally, cellular terminals have been commonly used in a wireless system, and a cellular terminal is normally connected to a facsimile machine or a modem, as shown in FIG. 1. FIG. 1 illustrates a connection between a cellular terminal and a facsimile machine or a modem.
When a cellular terminal 10 and a personal computer 30 are connected, for instance, the connection is made by a cable 40 via an adapter 20 such as a PC card. Accordingly, audio communication and data communication are carried out in separate structures.
In the WLL, on the other hand, a facsimile machine and a modem are connected to a subscriber unit, as shown in FIG. 2. FIG. 2 illustrates connections between a subscriber unit and a facsimile and a modem.
A subscriber unit 50 is provided with separate connectors for telephone, facsimile, and data communication. It is necessary to select a destination for each connector to be connected to a telephone machine 60, a facsimile machine 70, and a personal computer 80. This is because different processes are performed for audio communication and data communication in the subscriber unit 50, and it is necessary to switch the process.
A two-wire public line is provided with a connector 90 as shown in FIG. 3, and the telephone machine 60, the facsimile machine 70, and the personal computer 80 can be connected to the connector 90. Accordingly, a subscriber does not need to select the connector of the destination to connect the telephone machine 60, the facsimile machine 70, or the personal computer 80 to the two-wire public line.
In the WLL, on the other hand, the subscriber unit 50 is provided with the separate connectors for telephone, facsimile, and data communication, as shown in FIG. 2. Therefore, it is necessary to select a destination for each connector to connect the telephone machine 60, the facsimile machine 70, or the personal computer 80.
For common carriers to secure more subscribers, it is essential to eliminate the trouble of separation connections in the WLL. If the connections in the WLL cannot be made as easily as connections on the two-wire public line, it will be difficult to persuade subscribers to switch from the two-wire public line to the WLL system.
A general object of the present invention is to provide wireless systems in which the above disadvantages are eliminated.
A more specific object of the present invention is to provide a wireless system that comprises a subscriber terminal and a base station which can switch the communication mode based on the type of a signal inputted into the system.
The above objects of the present invention are achieved by a subscriber terminal comprising:
a connecting unit to which a device for outputting an audio signal or a data signal is connected;
a tone detecting unit that detects the type of a signal inputted through the connecting unit;
a signal path switching unit that switches the signal path between an audio signal path and a data signal path;
a control unit that controls the signal path switching unit based on the detected type of the signal; and
a communication unit that is wirelessly connected to a general public line network.
By switching the signal path between the audio signal path and the data signal path based on the detected type of the inputted signal, a user can connect either an audio signal outputting device or a data signal outputting device to the signal path switching unit without selecting the corresponding connecting unit. Accordingly, a user can easily connect either an audio signal outputting device or a data signal outputting device to the subscriber terminal of the present invention.
The above objects of the present invention are also achieved by a base station comprising:
a tone detecting unit that detects the type of a signal inputted from a general public line network;
a signal path switching unit that switches the signal path between an audio signal path and a data signal path;
a control unit that controls the signal path switching unit based on the detected type of the signal; and
a communication unit that is wirelessly connected to a subscriber""s home.
By switching the signal path between the audio signal path and the data signal path based on the detected type of the inputted signal, communication can be carried out with either audio signals or data signals in the same wireless system.
The above objects of the present invention are also achieved by a wireless system comprising:
a subscriber terminal that is connected to a device that outputs an audio signal or a data signal, and switches the signal path between an audio signal path and a data signal path based on a type of a signal inputted from the device; and
a base station that switches the signal path between an audio signal path and a data signal path based on a type of a signal inputted from a general public line network,
wherein the subscriber terminal is wirelessly connected to the base station.
By switching the signal path between the audio signal path and the data signal path based on the detected type of the inputted signal, wireless communication can be carried out without encoding data signals at high compression rate.
The above objects of the present invention are also achieved by a communication mode switching method, comprising the steps of:
selecting an audio signal path as an initial state from signal paths of a subscriber terminal and a base station;
detecting a type of a signal inputted into the subscriber terminal and the base station;
switching the signal path between the audio signal path and a data signal path based on the detected type of the signal; and
carrying out wireless communication between the subscriber terminal and the base station via the switched signal path.
By switching the signal path between the audio signal path and the data signal path based on the detected type of the inputted signal, wireless communication can be carried out between the subscriber terminal and the base station with either audio signals or data signals.
The above and other objects and features of the present invention will become more apparent from the following description taken in conjunction with the accompanying drawings.